Reference
Anhidrosis
Anhidrosis is the inability to sweat normally, meaning little or no sweat is produced. Because sweating is a key cooling method, this can interfere with the body's temperature control.
Anhidrosis can affect a small patch of skin or a wide area, and its causes range from nerve and skin conditions to certain medications. When the body cannot sweat enough, it may struggle to shed heat, raising the risk of overheating during exertion or hot weather. The absence of sweat is sometimes less obvious than excess sweat, so it can go unnoticed until heat becomes a problem. It sits at the far end of a spectrum, with reduced sweating as a milder version. Symptoms like feeling flushed, dizzy, or overheated in warm conditions can be the first hints. Reduced or absent sweating that affects cooling is worth medical attention. The name joins a prefix meaning without to the root for sweating. Unlike heavy sweating, which is hard to miss, too little sweating can hide until heat exposes it. This is why it can be more dangerous in some settings than excess sweating.
Anhidrosis is the inability to sweat normally, meaning little or no sweat is produced. Because sweating is a key cooling method, this can interfere with the body's temperature control.
What anhidrosis means
Anhidrosis can affect a small patch of skin or a wide area, and its causes range from nerve and skin conditions to certain medications. When the body cannot sweat enough, it may struggle to shed heat, raising the risk of overheating during exertion or hot weather. The absence of sweat is sometimes less obvious than excess sweat, so it can go unnoticed until heat becomes a problem. It sits at the far end of a spectrum, with reduced sweating as a milder version. Symptoms like feeling flushed, dizzy, or overheated in warm conditions can be the first hints. Reduced or absent sweating that affects cooling is worth medical attention. The name joins a prefix meaning without to the root for sweating. Unlike heavy sweating, which is hard to miss, too little sweating can hide until heat exposes it. This is why it can be more dangerous in some settings than excess sweating.
In practice
Someone who stays dry and overheats easily during exercise, while others around them sweat, may be experiencing anhidrosis. The mismatch, feeling very hot yet remaining dry when exertion should produce sweat, is a clue that the cooling system is not responding as expected. A patch of skin that never sweats after an injury or in a skin condition can be a localized example.
Frequently asked questions
Why is anhidrosis a concern in the heat?
Without adequate sweating, the body loses a major cooling tool. It can overheat more easily during exertion or hot weather as a result.
How is anhidrosis different from hypohidrosis?
Anhidrosis means little to no sweating. Hypohidrosis means sweating that is reduced but still present, a milder point on the same spectrum.
Sources & further reading
Reputable organizations with more on sweating and related topics. Offered for further reading and general education, not as citations for any specific claim on this page.
General educational information about sweating. Not medical advice, and not a substitute for diagnosis or treatment by a qualified healthcare professional.